Heavy equipment ongoing maintenance

The situation

Construction customers who own Heavy Equipment (Dozers, Graders, haul trucks, etc.) need to perform maintenance on an ongoing basis. As the equipment is used, there are components that see damage if a bearing fails or if seals damage a shaft area. This can cause the equipment to be down for service (lack of revenue) or if a seal fails, oil is leaking at a work site (environmental issue). We have found that customers will often have their own heavy duty mechanics or hire 3rd party companies to take their equipment apart and have it repaired. Once repaired, they re-assemble and put back into service to generate revenue.

The task at hand

D8, D9, D10 Final Drive Hubs.

We have customers with multiple models of Dozers for moving material. As they are used, the main drive unit that drives the tracks (called a Final Drive Hub) is worn in many ways. The bearing fits are damaged and/or oversized, the Duo-Cone Seal area is damaged and needs replacement, segment holes are oblong/worn out of round, and the OD of Final Drive Hub flange is damaged from loose Segments. Our role is to repair the Final Drive Hub back to OEM standards and tolerances and do it as quickly as possible as down-time results in significant losses in revenue.

The action plan

With the support of our customer, we confirmed the Final Drive OEM dimensions and tolerances, performed a detailed inspection and proceeded to provide repairs. The bearing fits were machined oversize so we repaired with a special low temperature welding process/special material (tougher and harder than the parent material) and finish machined back to tolerance. The Duo-Cone Seal area was removed and a new insert was installed. We replaced the flange segment holes with engineered inserts at the correct ID and tolerances, and the OD of Final Drive hub flange was machined down and built back up with a tougher, more durable alloy and finish machined to size.

The results

We saw reduced average turnaround time to 2-4 weeks depending on the scope of damage, and the average cost was 30-60% of the cost of a new replacement. New Final Drive Hubs are difficult to find due to supply chain issues so repairs were highly beneficial, and the bearing fits and OD of Flange alloy repairs lasted 2-3x longer than original equipment. Our customer has now established a standard repair process for these units – Call HIH. The final drive hubs we repaired are seeing less damage when they are coming back out of service and, therefore, reducing the cost of future repair.